Error messages generated too eagerly #85
Comments
jstolarek
added a commit
that referenced
this issue
Jun 15, 2018
Unification wrapper in typeSugar is now separated into:
* unification function returning a data type indicating success
or failure
* worker for raising an error
* wrapper around the above two functions that restores previous
behaviour of unify wrapper
* unifyOr combinator that tries to unify first pair of types and if
that fails it tries the second pair, without generating an error
message for the first failed unification
This partially fixes #85. build_tyvar_names is still called too eagerly
to generate variable names that are not getting displayed. Reason
remains to be investigated.
jstolarek
added a commit
that referenced
this issue
Jun 26, 2018
Generate error messages lazily. Fixes #85. Unification wrapper in typeSugar is now separated into: * unification function returning a data type indicating success or failure * worker for raising an error * wrapper around the above two functions that restores previous behaviour of unify wrapper * unifyOr combinator that tries to unify first pair of types and if that fails it tries the second pair, without generating an error message for the first failed unification
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
When working on #43 I noticed that function generating error messages (a.k.a. gripers in
typeSugarmodule) are called several times even though only one error message gets printed. @slindley says this is caused by unification doing backtracking: error messages are generated and thrown as exceptions, they get caught and another attempt at unification is made. It would be much better to generate error messages lazily, ie. only when they are actually going to get printed.The text was updated successfully, but these errors were encountered: